587 FXUS61 KBOX 062346 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 746 PM EDT Tue Sep 6 2022 .SYNOPSIS... Steady rain will taper off from northeast to southwest through the first part of the evening, but a few spot showers will remain possible into Wednesday. High pressure builds over the region Thursday, and persists through this weekend with dry weather and normal to slightly above normal temperatures. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 740 PM Update... Forecast remains largely on track. Made some slight adjustments to the PoPs to reflect the widespread nature of light showers or drizzle. Showers should gradually come to an end from north to south overnight as high pressure builds in. But low pressure off the Jersey coast will reinforce the onshore flow and keep the low-level moist with the chance for spotty drizzle or light showers. Temps will not fall much tonight, bottoming out in the upper 50s to low 60s. PREVIOUS DISCUSSION... 325 PM Update... * Steady rain tapers off during the first half of the evening Low pressure will exit the south Jersey coast early this evening and drop further southeast tonight. At the same time...high pressure over Maine will nose southward. This will bring an end to most of the widespread rain from northeast to southwest during the first half of the evening; as somewhat drier mid-level air continues to work in from the north. However, weak mid level low pressure to our south will help to generate moist low level onshore flow. This will result in lingering low clouds, a few spot showers and perhaps some spotty drizzle/fog patches overnight. So while much of the later evening and overnight hours will turn out dry; a few spot showers and perhaps some spotty drizzle will remain possible. Overnight low temps will bottom out mainly in the upper 50s to the lower 60s. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Wednesday... High pressure across northern New England will combined with low pressure off the mid-Atlantic coast on Wednesday. This will continue to generate a low level onshore ENE flow of air into the region. This will keep skies rather cloudy on Wednesday, but perhaps we see a few breaks develop late in the afternoon/early evening across northern MA as somewhat drier air tries to work into the region. While most of the day will feature dry weather in a given location; a few spot showers will also be possible mainly across eastern CT/RI and SE MA where moisture will be bit deeper. That being said; even in these locations dry weather will dominate the vast majority of the time. High temps will mainly be in the upper 60s to the lower 70s. Wednesday night... Drier low level air continues to slowly work in from the north from a high pressure system in northern New England. This should result in partial clearing at least northwest of I-95 by daybreak Thursday. Dry weather expected across much of the region, but may have a band of showers approach the south coast, Cape and Islands. This will depend upon northwest extent of the low level circulation from the distant offshore low pressure system. Overnight low temps will mainly be in the 50s to near 60. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Highlights * Some spotty rain showers may linger across portions of the Cape/Islands Thursday, but no washouts. * Mainly dry and quiet weather for the rest of the week with high pressure in control with a warming trend into the weekend. * Turning more unsettled early next week. Thursday into Friday... A shortwave trough will cross New England on Thursday, helping to push the frontal boundary that has been stalled near the Mid Atlantic coast further offshore. Further to the south, distant Earl should start turning northeastward after moving close to Bermuda. While this would help maintain the low-level northeast flow for our area through Friday, model sounding cross section indicates a gradual drying of the 925-700mb levels. This should allow for a mix of sun and clouds especially away from the immediate south coast. With 925mb temps +14 to +17C, highs should top out mainly in the mid 70s, except upper 70s across the CT valley on both Thursday and Friday. Saturday into Sunday... H5 ridge builds into New England this weekend. With surface high pressure in control and 925mb temps +18 to +20C, expect mainly dry weather and near seasonable highs in the upper 70s to low 80s through the weekend. Monday into Tuesday... Models indicate a H5 low closing off over the Great Lakes and moving into the Ohio valley. Low level flow turns south to southwest and there would be an increasing chance for unsettled weather early next week. Given the model uncertainty and that we are more than five days out, mainly stuck to blended guidance for early next week. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. 23z TAF Update... Tonight...Moderate Confidence. Bulk of the steady rain ends early this evening from NE to SW, but a few showers along with spotty drizzle will remain possible. MVFR-IFR ceilings dominate with some patchy fog possible too. NE winds 5-10 knots. Wednesday...Moderate Confidence. MVFR-IFR conditions early in the morning will tend to improve to mainly MVFR-VFR thresholds as the day wears along from north to south. Specific timing a bit uncertain, but improvement should occur from the north as drier air gradually presses into the region. A few spot showers and drizzle will remain possible mainly across southeast New England, but the vast majority of the day will be dry in a given location. NE winds 5-15 knots. Wednesday night...High Confidence. Remaining lower ceilings will tend to improve to mainly VFR during the evening/overnight hours as drier air continues to advect in from the north. A few showers still possible across the southeast New England coast. NE winds 5-10 knots. KBOS Terminal..Moderate confidence in TAF. KBDL Terminal...Moderate confidence in TAF. Outlook /Thursday through Sunday/... Thursday: VFR. Breezy. Thursday Night through Sunday: VFR. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight through Wednesday night...High Confidence. High pressure over northern New England coupled with low pressure emerging off the mid-Atlantic coast will generate a continued NE flow of air right through Wed night. Have hoisted SCA headlines for our southern outer-waters where we expect 3-5 foot seas and NE wind gusts up to 25 knots tonight into Wed night. It will be marginal for some of our western and southern sounds, but some marginal 25 knot NE wind gusts are possible on Wednesday. Later shifts may have to consider expanding the small craft headlines a bit further northwest as it will be a close call. Outlook /Thursday through Sunday/... Thursday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers. Thursday Night through Friday: Winds less than 25 kt. Seas up to 5 ft. Friday Night: Winds less than 25 kt. Areas of rough seas. Saturday through Sunday: Winds less than 25 kt. Seas up to 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 8 AM EDT Thursday for ANZ254>256. && $$ SYNOPSIS...Frank/Chai NEAR TERM...Frank/Chai SHORT TERM...Frank LONG TERM...Chai AVIATION...Frank/Chai MARINE...Frank/Chai